Axial-flow turbine.



-A. A. WILTON VAN REEDE; czN.

AXiAL FLOW TURBINE.

APPLICATION FILED JAN. I7. 1916.

1 ,205,062 Patented Nov. 14, 1916.

sans PATENT onnrcn.

EJIRIANUS ANTHONIE WILTON VAN REEDE, CZN., h SCHIEDAM, NETHERLANDS.

I AXIAL-FLOW TURBINE.

panacea. I

Specification of Letters Patent.

Patented Nov. 14, 1916.

Application filed .Ianuary 17, 1916. Serial No. 72,564.

.To all whom iii-may concern:

Be it known that I, Annmnos Ax'rnomn WILToN VAN Ran-on, Czn., subject of the Queen of the Netherlands, residing at Schiedam, Netherlands, have invented certain new and useful Improvements in Axial-Flow Turbines; of which the following is a specification.

This invention relates to axial flow turbines of the type having two oppositely run- 1 balanced by passing the steam in two opposite flows through the blades, each flow acting' on half the number of rows of blades. This way of balancing the axial pressure,

however, requires complicated constructions and excludes the possibility of a compact construction, which is this invention.

According to the invention the axial pressure is balanced by providing partition disks in one of the rotors, said disks dividing each of the two symmetrical halves of the rotors into a number of compartments, in each oi which the steam acts on two opposite walls, so that there is noresulting axial pressure. These partition disks may be connected to the hub of the inner rotor and be one of the objects of made to fit steamti'ght in the drum of the outer rotor, but it is preferred to connect the partition disks to the inner wall of the drum of the outer rotor and to makethem fit steamtight around the hub of the inner rotor.

It will be understood that it is of supreme importance for the good working 'of the pressure balancing arrangement, that the compartments formed by the partition disks and by the inner wall of the outer rotor drum or the outer surface of the inner rotor I hub be practically absolutely steamtight, as

any leakage of steam from one of these compartments into the adjoining one would cause a difference between the total pressures acting on each of the two opposite walls of vsaid compartment and thus would derogate from the theoretically absolute balancing of :the axial pressure. On the other hand, in view of the compact construction aimed at the packing means should take. as little space as possible.

According to the invention the packing means comprise simple flat rings of brass or ,like metal mounted on the hub of the inner rotor, so as to cover with their sides the joints to be packed. Experience has shown that these rings, being pressed onto the joints to be packed by the steam pressure and thus automatically ground in, form a packing which is almost absolutely steamtight.

In connection with the packing by means of flat rings of very small axial dimensions on the one hand, and with the considerably larger axial dimensions of the rotors at the periphery of the blade wheels on the other hand, the. central portions of the partition disks and the blade wheels are according to this invention bent inward in the direction.

of the plane or, symmetry of the turbine, whereas the outer portion is bent outward so as to leave suflicient space for the subsequent rows of blades and for the axial gaps, by which the steam is allowed to enter into the balancing compartments. The space thus obtained at the outer side of the central portion of the rotors is used to lodgethe bearings, preferably ball bearings, 2'. 6., reckoning from the middle to the ends of the rotors first the bearings between inner and outer rotor and then those between the outer rotor and the casing of the turbine. In this way the bearings are surrounded by dead steam,

which is by far preferable as compared to known arrangements, wherein the bearings are exposed directlytolive steam;

To avoid direct contact of the live steam with the parts carrying the inner ball-races,

(the steam being supplied to the blade wheels by means of a bore or bores in the shaft) according to this invention said bore or bores 1s or are provided with steam supply pipes having a diameter substantially smaller than the bore or bores, so as to obtain an insulating space between the walks of the steam supply pipesand the she V 9 mos In reversible turbines, which are runmng" as a rule in one direction, for example, marine turbines, it is suflcient in most cases to provide an insulating ace onl .about the steam supply correspon ing to t e usual direction of rotation.

As the difierence between the presuras in the adjoining compartments of the two rotor-halves is greater than the diilerence between the reaures in adjoinin com artments of tlie same rotor-half, t e ac ing between adjoining com artments o diflerent rotor-halves shoul be very eflective. According to the invention, a very eflective acking in this place is obtained by formin the partition between the two turbineha ves as a double disk, preferably connected to the outer rotor just as the other artition disks and being likewise ack by fiat rings covering the joints at t e hub of the inner rotor. he compartment inclosed by the double disk is brought into communication with the'condenser, so that leakage of steam from one of the turbine halves into the other is practicall rendered impossible.

The-invention will described with reference to the annexed drawing which shows, by way of example, a horizontal sectional view of a marine turbine embodying the invention.

In a casing l the shaft'3 of the symmetrical outer rotor 3 is supported in ball bearings 2, 2. The shaft 3 of the outer rotorhas a bore containing the shaft 4 of the symmetrical inner rotor 4, the shaft 4 being supported in ball bearings 5, 5 connected to the outer rotor. The blade rims 6 carrying the blades 6 of the outer rotor are connected to the inner surface of the outer rotor drum 3; the blade wheels 10 carrying the blades 7 of the inner rotor are connected to the shaft 4 of the inner rotor. Rows of blades (3 are arranged to alternate with rows of blades 7, so that flows of steam passing axially through the blades alternately pass blades of either rotor.

Partition disks 8 are connected to the inner surface of the outer rotor drum 3 and divide each of the symmetrical halves of the outer rotor into three balancing compartments.

As shown in the drawing a wide axial grep 23,is left open in every compartment tween the last row of blades in said compartment and the next partition disk, said gap allowing steam to enter into the balancmg compartments. Holes 9 are provided in the blade wheels 10 in each compartment so as to allow the steam in such com artments to influence equally both side-wa ls 8. The pressures on opposite side-walls of each compartment being equal, there is no resulting pressure in either direction.

The packing of the partition disks at their inner edges, around the hub of the inner rotor, is effected by means of flat rings 22 of bralm or like comparatively soft metal, mounted so as to cover the joints between the hubs and the disks 8.

The central rtions of the partition disks 8 and of the ward in the direction of the lane of symmet of the rotors, whereas t ese disks and whee 'at their periphery are bent outward so as to leave suflicient made for the blades 6 or 7 and the axial gaps 23 at the end of each balancing compartment. The thus obtained at the outer side of each rotor-half is used for lodging the bearings 5, 5 supporting the inner rotor in the outer rotor and the bearings 2, 2 supporting 'the outer rotorinthe casing 1.

Steam may be supp ed to the left half of the rotors (for of a marine turbine by means of a pipe'15, placed in a bore of the shaft 4 of the inner rotor and ha an outer diameter subdan' tially smaller t an the said bore, so that an annular space 11 which is left between the steam supply pipe and the shaft 4 forms an effective heat insulation for the ball bearen steam is supplied by the inlet 12 to the annular conduit 11 instead of by the inlet 16, the right half of the turbine is start ed, the blades 6, 7 of said half being bent so as cause a rotation of the rotors in-a direction opposite to that caused bythe blades 6, 7 of the left half. Aathe right half of the marine turbine shown in the drawing is designed as an astern turbine and, as such, isonly set to work exceptionally, no means are provided in this case to insulate the bearing 5 from .the supply of live steam. If required, however the in-- ner supply pipe 1 5 may be surrounded by' a second pipe, serving as supply conduit for, the right half of the turbine and the outer diameter of this second pipe may be chosen so as to leave an insulatin ace between said pipe and the shaftof t e inner rotor.

In the drawing, the steam supplied by the pipe 15 to the left half or by the'annular conduit 11 to the ri t half of the turbine passes through radia conduits 18 formed in the inner end walls of the halves of the inner rotor 4 to nozzles 14, from which the steam is directed to the alternating rows of going. ahead, in'the case lade wheels 10 are bent.in-

blades 6, 7, either of the left or of the right half turbine. After having passed through all the rows of blades the steam reaches the exhaust 18 through holes 17 in the mid walls of theo'u ter rotor.

The two halves of the rotors are separated by a double artition disk 19 connected to the inner sur ace ofthe outer rotor and inclosing a compartment 20 which communicates with the exhaust 18 by holes 21 in the drum 3 of the outer rotor. At its inner edge the; double disk 19 is alsopacked by flat rings 22, covering the joints between the said disk and the hub of the inner rotor.

\Vhat 1 claim as my invention and desire to secure by Letters Patent is:-

1. An axial flow turbine comprising two symmetrical halves and two oppositely running rotors. partition disks in each of the symmetrical halves adapted to divide each half into a plurality of balancing compartments, and connected to one rotor and making a stean'itigl'it joint with the other rotor.

2. An axial flow turbine comprising two symmetrical halves and two oppositely running rotors, partition disks in each of the symmetrical halves adapted to divide each half into a plurality ol balancing compartments, and connected to the inner surface of the outer rotor-drum, and a packing comprising fiat rings of soft metal extending across the joints between the inner edges of the partition disks and the hub of the inner rotor.

3. An axial flow turbine comprising two symmetrical halves and two oppositely running rotors, partition disks dished inwardly toward the plane of symmetry connected to one motor and making a. steamtight joint with the other rotor, and llade wheels dis posed between the said disks and similarly dished.

4. An axial flow turbine comprising two symmetrical halves and two oppositely running rotors, partition disks dished inwardly toward the plane of symmetry, connected to one rotor and making a steamtight joint with the other rotor, blade wheels disposed between the said disks and similarly dished and a packing comprising flat rings of soft metal extendin across the joints between theinner edges of the partition disks and the hub of the inner rotor.

An axial flow turbine comprising two symmetrical halves and two oppositely running rotors, partition disks dished inwardly toward the plane of symnwtry, connected to one rotor and making a steamtight joint with the other rotor, blade wheels disposed between the said disks and similarly dished, and ball-bearings in the central spaces provided by the dishing of said disks and bladewheels.

(3. An axial flow turbine comprising two symmetrical halves and two opposite-1y running rotors, partition disks dished inwardly toward the plane of symmetry, connected to one rotor and making a steamtight joint with the other rotor, hollow shafts carrying the rotors, steam supply pipes within said shafts having an annular insulating space between them and the walls of the shafts, and blade wheels disposed between the said disks and similarly dished 7. An axial flow turbine comprising two symmetrical, halves and two oppositely running rotors, partition disks in each of the symmetricalhalves, and a double partition disk centrally arranged between the two halves. and inclosing a space communicating with the exhaust.

In testimony whereof I have hereunto set my hand.

ADRIANUS ANTHONIE WILTON VAN REEDE, CZN. 

